Sealant for pushdown gate in a can lid

ABSTRACT

A sealing arrangement for a pushdown gate in a can lid of the type where the gate is defined by a score line in the face of the lid which is torn and severed when the gate is pushed into the can. This score line outline of the gate is located in an indentation in the surface of the can and at one point, the score line is lanced to facilitate its tearing action. The gate structure in the can lid further includes a lapping portion between the gate itself and the can lid, either with the gate underlying an aperture in the lid or forming an underlying tab which surrounds the lanced opening. A settable sealer-filler may be applied to the lid at the indentation as a liquid to flow between the lap and into the lanced opening. Thereafter, when the sealer-filler sets, it will effectively harden to produce a positive seal at the lanced opening.

United States Patent 1191 Klein 1451 Sept. 16, 1975 SEALANT FOR PUSHDOWNGATE IN A CAN LID [76] Inventor: Gerald B. Klein, 13451 Stuart Ct.,

[52] US. Cl 220/268; 220/265 [51] Int. Cl. B65D 43/02 [58] Field ofSearch 220/27, 45, 46 R, 46 MS,

[56] References Cited UNITED STATES PATENTS 178,544 6/1876 Merrill220/45 3,794,206 2/1974 De Line 220/48 Primary ExaminerWilliam l; PriceAssistant ExaminerRo E. Hart Attorney, Agent, or Firm-Van Valkenburgh,Lowe & Law

[ 57 ABSTRACT A sealing arrangement for a pushdown gate in a can lid ofthe type where the gate is defined by a score line in the face of thelid which is torn and severed when the gate is pushed into the can. Thisscore line outline of the gate is located in an indentation in thesurface of the can and at one point, the score line is lanced tofacilitate its tean'ng action. The gate structure in the can lid furtherincludes a lapping portion between the gate itself and the can lid,either with the gate underlying an aperture in the lid or forming anunderlying tab which surrounds the lanced opening. A settable sealer-3,298,87O 1/1967 Sabatino.... 220/45 filler may be applied to the lid atthe indentation as a 3,334,775 8/1967 Klein 220/48 liquid to flowbetween the ,lap and into the lanced 3,485,411 12/1969 Brown 220/48opening. Thereafter, when the sealer-filler sets, it will 3,628,688 1 71aggard-m. 220/46 R effectively harden to produce a positive seal at the3,630,408 12/1971 Elser... 220 27 lanced Opening 3,760,752 9/1973 Geiger220/27 3,779,417 12/1973 Klein 220/48 7 Claims, 29 Drawing Figures L/ Gi PATENIEU @975 3805513 Fig. IO

PATEIHEU 1 975 nan g 1 7 i 7 1 '17 z 2 T 50 5o 53 Fig. 16 Fig. 17

765 L") 7 6" mg Fig. I8 Fig. I9

SEALANT FOR PUSI-IDOWN GATE IN A CAN LID This invention relates to canlids having gates in the surfaces of the lids which are pusheddownwardly into the cans to open them, and more particularly to meansand materials for sealing such gates until they are opened.

The invention may be used with gated can lids wherein the gate isintegral with the lid and is formed at an opening or aperture in the canlid beneath an underfolded, interconnecting spacer strip about thisaperture, of the type set forth in the patent issued to myself andKenneth E. Harper, U.S. Pat. No. 3,334,775, on Aug. 8, 1967. Theinvention may also be applied to similar gated can lids where portionsof the gate and lid lap each other at the section to be sealed, ashereinafter set forth.

To form a push-down gate in a canv lid,- an important step is to cut ascore line to define the outline of the gate, leaving an uncut hingeportion so that the gate may separate from the lid and swing about thehinge portion as it is pushed downwardly. The present invention comesinto play where a short portion of the gate outline is severed from thelid, at this score line, preferably at the end opposite to the hinge, asby an operation which may be called lancing. When a short portion of thescore line is thus lanced, the gate will easily tear away from the lidat the remaining portion of the score line. However, the score line atthis lanced portion must be securely sealed to prevent the contents ofthe can from leaking, even when the can is subject to internal pressureand/or is handled in a rough manner.

As will hereinafter appear, this scoring and lancing is contemplatedwith several types of gates, one of which is exemplified in the abovementioned patent, and the basic' feature of such types considered isthat an edge of the gate will lap a portion of the can lid at thelocation where the can lid is lanced and sealing is required.

The invention is also concerned with a gated can lid where the gate isformed beneath an underfolded strip at the aperture of the opening andis pushed downwardly into the can to open it. The gate is necessarilyimmersed in the liquid contents of the can and accordingly,cleanliness-and sanitation are important. In the construction disclosedin the US. Pat. No. 3,334,775, the underfolded strip and the gatebeneath it creates a shallow pocket which could be'a trap for substanceswhich are contaminants. Regardless of the type of gate used,contaminants may adhere to the gate surface for the contaminants may besmall solid particles or drops of various types of liquids which mayaccidentally fall onto the gate in the can lid.

The present invention was conceived and developed with the foregoingconsiderations in view and comprises, in essence, the use of a suitableinert sealer-filler which is applied to and about the gate in the canlid in such a manner as to fill any underfolded lap or channel betweenthe gate and the lid. At the same time, the sealing substance musteffectively fill and seal the lanced portion of the .score line definingthe outline of the gate, and in some applications, even flow through thelanced opening and into a substantial portion of the score line and tosurfaces adjacent to the score lineto protect the exposed metal surfaceat this score line and any adjacent metal surfaces where the coating ofenamel, used with can lids of this type, is ruptured or abraded duringforming of the gate.

It follows that an object of the invention is to provide, in a gated canlid having a gate which underlies, or partially underlies, an aperturein the lid and which is opened by being pushed downwardly, a novel andim-- proved arrangement of a sealer-filler in the can lid aperture, orchannel, which eliminates the possibility of contaminantsubstances-being lodged therein.

Another object of the invention is to provide in a gated can lid havinga partially lanced score line which extends about the periphery of thegate which is broken as the gate is pushed downwardly into the can, anovel and simplified arrangement of a filler and sealer to effect aleakproof fit of the gate at both the lanced portion of the score lineand also at any other sections of the score line where it may have beenruptured as during the manufacture of the lid.

Another object of the invention is to provide in a gated can lid havinga gate or a portion of a gate formed beneath an underfolded spacer stripabout an aperture in the face of the can lid ,with the outline of thegate being defined by a score line beneath this underfolded spacer stripand with lanced openings at the score line to facilitate tearing thescore line when the can.is being opened, a -novel and improved method ofsealing this lid by using selected meltable or thermoplastic, or liquidthermo-setting types of natural or synthetic materials as afiller-sealer to close the lanced opening or any other break at thescore line, which takes advantage of the, capillary action of a fluidsealant to seep into the lap between the spacer strip and gate, throughthe lanced opening, and thence into the score cut to effect a positiveand complete seal, completely about the gate and which also will flow toform fillets to seal off and overlie, recessed portions of theapertureexposed to possible contaminents. I I

Another'object of the invention is to provide in a gated can lid of thetype considered, asimplified mode of sealing and filling thegatedaperture, which is quick, reliable and economical. 1 3

With the foregoing and other objects in view, my present inventioncomprises certain constructions, combinations and arrangements-of partsandelements as hereinafter described, defined -in the appended claims,and illustrated in preferred embodiment by the accompanying drawing inwhich:. I p H FIG. 1 is a perspective view of the can having a pushingate formed below a round aperture with an underfold of .the can lid.

. FIG. 2 is a plan view of the can illustrated at no. '1 to show the lidand gate therein with dotted lines indicating the outline of the gatepanel beneath the aperture in the canlid.

FIG. 3 isa bottom view ofa portion of the can lid shown at FIG=2illustrating the gate panel and a score line which separa es the gatefrom the edge of the panel underneath the aperture.

FIG. 3a is a fragmentary viewof a portion of the showing at FIG. 3 buton a greatly enlarged scale to show the lance in the score line.

FIG. 4 is a sectional view of a fragment of the can lid as taken fromthe indicated line4-4 at FIG. 2, but on a greatly enlarged scale withportions broken away to conserve space and with a sealer-filler materialwithin the recess formed by the gate beneath the aperture to emphasizethe manner in which this sealer-filler will flow into the crease beneaththe spacer strip and the gate and through the lanced portion of thescore line.

FIG. 5 is a fragmentary sectional view as taken from the indicated line5-5 at FIG. 2 but on a greatly enlarged scale to show the manner inwhich the sealerfiller lies upon the gate and flows into the score lineat the underside of the gate.

FIG. 6 is a fragmentary view similar to FIG. 3a but showing the mannerin which the sealer-filler material can flow through the lanced portionand about 'the score line. i

FIG. 7 is a fragmentary detail similar to the showing at FIG. 5 butillustrating a modified embodiment wherein the gate is formed within aninsert tab fitted into an opening in the can lid. I

FIG. 8 is a sectional view similar to FIG. 4, but showing a modifiedform of the gate panel with the center portion of the panel being raisedand with the sealerfiller being indicated as flowing into the channelbetween the aperture and the raised portion of the gate and over anextended area at the underside of the gate and adjacent portions of theunderfold and undersurface of the lid as may be obtained by fluxing thesame.

FIG. 9 is a plan view of a portion of a lid similar to FIG. 2 butillustrating a modified embodiment wherein the gate is formed with aninsert tab fitted into an opening in the can lid and with a channelformed in the lid about the edge of the tab to receive a sealer-filler.

FIG. 10 is a fragmentary, sectional view as taken from the indicatedline 1010 at FIG. 9 but on a greatly enlarged scale with portions brokenaway to conserve space and with "a sealer-filler material within thechannel between the gate and aperture and within the channel in the gatelid at the edge of the insert.

FIG. 11 is a plan view of a portion of a lid similar to FIG. 2, butillustrating a modified embodiment wherein the center of the gate israised as in'the manner illustrated at FIG. 8 and wherein a score is cutat the upper surface of the gate as indicated in dotted lines.

FIG. 12 is a sectional view of a fragment of the lid as taken from theindicated line 12l2 at FIG.-11, but on a greatly enlarged scale, withportions broken away to conserve space, with a sealer-filler materialwithin the recess formed by the gate beneath the aperture and with asmall portion of the sealer-filler material at the lanced section of thescore.

FIG. 13 is a plan view of a can lidsimilar to FIG. 2, but illustratinganother embodiment of the invention wherein a gate is defined by a scoreline within a channel at the upper surface of the lid andwith brokenlines indicating the location of an underlying tab at the lanced portionof the score line.

FIG. 14 is taken from the indicated line l4'14 of FIG. 13, but on agreatly enlarged scale with portions broken away to conserve space andwith a sealer-filler material in the channel at the outer surface of thelid and at a portion of the undersurface of the lid where the lanced,lapped section occurs.

FIG. 15 is an isometric view of a portion of the underside of the lid,on an enlarged scale compared with FIG.

13, to show the bottom of the channel and the undersurface of the gateand the offset tab.

FIGS. 16 19, inclusive, are fragmentary sectional views as taken fromthe indicated line l919 at FIG. 15, but depicting the steps of a methodwhich may be used to form the offset tab at the lanced portion of thegate.

FIG. 20 is a plan view of a can lid similar to FIG. 2 to illustrate yetanother embodiment of the invention wherein the gate panel is horseshoeshaped and modified in structure.

FIG. 21 is a plan view similar to FIG. 20, but showing a pair of smallergate panels which are U-shaped.

FIG. 22 is a bottom view of a portion of the can lid shown'at FIG. 20,but on an enlarged scale to illustrate the gate panel and a score lineand lanced portion of the score line.

FIG. 23 is a fragmentary sectional view as taken from the indicated line23--23 at FIG. 20, but on an enlarged scale and with portions brokenaway to conserve space.

FIGS. 24 and 25 are fragmentary sectional views as taken from therespective indicated lines 2424 and 25--25 at FIG. 20, but on anenlarged scale and with portions broken away to conserve space.

FIGS. 26 28 inclusive, are fragmentary sectional views depicting stepsof a method which may be used to form the gate shown at FIGS. 20 25.

Referring first to the embodiment shown at FIGS. 1 6 of the drawing, atypical can C is formed with a lid L which is of a common constructionexcept for a pushin gate G in the face of the lid. In the drawing thisgate and the aperture are illustrated as being'circular; however, it isto be noted that the gate and aperture may be oval, U-shaped,triangular, rectangular tear-drop or in any other suitable form.The-gate G is integral with the can lid L and it is formed byunderfolding and enlarging a portion of the lid to form a gate panel 20beneath an opening or aperture 21 in the can lid. The underfolded gatepanel 20 is separated from the lid L by a spacer strip 22 which extendsbeneath the can lid about the edge of the aperture-and above the edge ofthe panel 20. The outline of the gate panel 20 is defined by a scoreline 23 which is cut in the underside of the panel 20 in any suitablemanner, and directly beneath the spacer strip 22. As best illustrated atFIG. 3, this score line 23 terminates at each side of ahinge portion 24,which is preferably near the center of the lid. It is contemplated thatthe gate may be pushed downwardly into the can by tearing it away fromthe lid at the score line 23, but the gate will remain attached to thelid at this hinge 24.

To facilitate breaking the; connection of the gate to the lid at thescore line, a short portion of this score line is lanced or cut through,as at 25, preferably at the edge of the gate opposite the hinge 24. Itis to be noted that the continuity between the gate panel 20 and theouter portion of the underfold below the spacer strip 22 connecting withthe gate is not broken by this score line except at the lanced portion15 which cuts completely through the sheet material forming the gate andthe lid. The spacer strip 22 results from drawing and folding the lidmaterial to produce a gate panel 20 which is larger than the aperture21. This provides for a rounded, smooth surfaced aperture 21 at the foldwhere the spacer strip 22 joins with the lid L. This is advantageoussince such a fold will not cut the fingers of a person pushing the gateinto the can. At the same time, the underfold beneath the spacer strip22, wherein the gate is located, is larger in diameter than the aperture21 with its connection to the spacer strip being an outer edge fold 26as bestillustrated at FIGS. 4 and 5. This produces a fold 27 between thetop surface of the gate G and the undersurface spacer strip 22.

In the manufacture of a can lid, where the aperture structure, includingthe spacer strip, is drawn and folded, it is to be noted that this fold27 cannot be completely closed with an airtight fit and accordingly, itis illustrated with a portion of the lapping surfacesbeing separated ashort distance from each other. Actually the drawing is exaggeratedsomewhat for the lap or fold 27 is very narrow because the dies formingtheaperture and the gate beneath it will exert considerable pressure.against the lid, spacer strip and gate. However, no matter how tightlythe spacer strip bears against the gate panel, liquids which adhere tothe surface of the material forming this lid and panelcan seep betweenthe two members by capillary action. Such liquids may be contaminatingfluids such as dirty water or the like and if a drop of such a liquidwere to fall into the gate aperture, it would seep into this space andthence into the can when the gate is opened. Also, small particles, suchas dust, filings or the like can be lodged in the aperture against theedge of the spacer strip 22. Therefore-it is important to provide ameans to prevent such from occurring, because the gate must be cleanand'sanitary.

The present invention contemplates placing a liquid sealer-filler 30 inthe aperture 21, above the gate, which will flow into the fold 27between the spacer strip 22 and the edge of the gate panel G and alsoflow onto the lanced opening 25 to form a plug 31 to seal off thisopening, as hereinafter further described. This sealer-filler must thenset andharden to produce a smooth surfaced fillet 32 about the edge ofthe aperture which encloses the fold of metal at this edge 21. Thefillet will prevent contaminant liquids from seeping into the lap andalso prevent small solids from lodging against this aperture edge. Ifdesired, a sufficient amount of sealer-filler material may be providedto completely fill this aperture.

An ideal material for the sealer-filler may be selected from a number ofdifferent types of paraffin waxes which are comonly available. Onesuitable type is micro-crystalline paraffin wax. Paraffin waxes arepetroleum products and may be refined to the point where substantiallyall oils have been removed and the comparatively pure wax is white,odorless, tasteless and practically impervious to moisture. As such,paraffin waxes are widely used in the food and beverage industries forlining containers. These waxes will melt at-various ranges oftemperatures, to a liquid of low viscosity which has good adhesion andadsorption to metal surfaces. Paraffin and other types of synthetic ornatural waxes are commonly blended together to attain a selected degreeof hardness and resistance to cold flow when they cool and set. Atechnician skilled in-the'art can select various waxes and wax blends,suitable: for

the purpose at hand.

Other materials, such as natural and synthetic resins,

are also suitable for the filler-sealer. For example, a

number of polymeric sealants are known, such as a thermosettingpolyepoxide or a thermoplastic ethylene vinyl acetate copolymer. Suchmaterials must be meltable to a liquid or be liquid in an initial state.The liquid must have a low viscosity and an affinity for the'metal orcoated metal forming the lid and gate to produce the needed capillaryaction to form the fillet 32 to permit it to flow into the closelyspaced fold 27 between the spacer strip 22 and gate surface and thenceinto the lance opening 25. This material must then harden and set to astiffness sufficient to resist the pressures within the can to prevent aflowback ior leakage at the opening 25. Finally, the material must beacc'eptablefor use in dersurface of the can lid.

connection with beveragesand foods. A skilled technician caneasilyselect suitable resins for the purpose at hand knowing theconditions above stated.

The metals commonly used in the manufacture of can lids include aluminumand steel. Thus, paraffin waxes arepreferred for a sealer-fillermaterial since they have good affinity for, and good adhesion with thesemetals and conventional can lining materials, usually lacquers orenamels. v

When the sealer-filler consists of a wax-like material which must bemelted, its application includes the steps of heating the can lid to aselected temperature to permit the wax to melt and flow in place. Thisheating of the can lid may be one of the final steps in the manufactureof the lid and it can be accomplished in any suitable method such aspassing the lid through an oven, with, infra-red radiation, placing thelid upon a heat source plate, flame heating or heating by electricalinduction methods. It is important that the lids be heated quickly sincethey are ordinarily produced at a great rate and'a skilled operator canselect the best mode of heating the lids for any given productionoperation. The wax may be pre-meltedora small pellet of wax may beplaced on theheated lid, in the aperture, to melt and flow to the edgesof the aperture and underneath the lap 27 by capillary action.Thereafter, the lids will be cooled to permit the wax to setto completethe operation. Y

When a microcrystalline wax was used to seal can lids, as abovedescribed it was discovered that the flow of waxwas remarkably uniformand that wax which would flow into the fold 27 by capillary action wouldeasily andrapidly flow through the lance 25 and into the score line 23about the edge of the gate as a bead 33 which overlays the exposed metalin the score line. It was further ascertained thatvif a fluxing agentwere used, the wax would not only follow the score line where exposedmetal. existed, but also would spread about the undersurface of the gateand lid where the fluxing agent was applied.

Such a flux may be applied during the operations of drawing and shapingthe can lid to form the aperture 21, the spacer strip and the gatebeneath the lid because it is necessary to use a lubricant on the dieswhich form the. gate beneath the lid and such lubricant may be thefluxing agents. A naptha-wax blend is a commonly used type of lubricantand is a good fluxing agent which will permit the paraffin to flow overa selected area at each-side of the score line,as hereinafter furtherdescribed. Such a fluxing agent, a naptha-wax blend, can also be printedonto a selected portion of the un- Where a thermosetting type of asynthetic resin plastic is used:.to effect a seal, such as with a twocomponent thermosetting resin such as a polyepoxide which is initiallyin. a liquid phase but which will thereafter set up, the same simpleprocedure may be used. A drop of the liquid resin is placed in theaperture to flow into the A uid resin will be permitted to set into ahard resistant material, either bygheat action or through reactions"over a lapse of time, according to conventional practice. It is to benoted that when a material other than a paraffin wax is used, the flowof material from the gate and into the raw metal score line may not bevery effective and hence, a respray operation which applies a thincoating of paraffin, or other coating conventional in can makingpractices, to the underside of the lid may be necessary.

An important factor in the present invention resides in the location ofthe lanced opening 25 which is at only a very small portion of the gateperiphery. The lanced opening lies against the lapped fold 27, thespacer strip 22 forming a backing surface at the fold. Thus, the plug 31in the lanced opening is reinforced by the lap 27 to withstand pressurewithin the can. Should the opening 25 be located in a portion of the lidwhere another closely lapped backing surface does not exist, the plug31, formed by the wax seal, cannot resist the shear forces produced byany substantial pressure within the can; after a short period of time,such a plug-like seal would give way. However, with the closely lappedbacking surface, exemplified at FIGS. 4 and 10, the wax plug 31 mustfirst flow between two closely spaced surfaces, the spacer strip 22 andthe gate panel G, before giving way. Moreover, pressure within the canwill tend to squeeze these surfaces together. Thus, the plug 25 canresist substantial pressures within the can.

Various modified arrangements of a gate in a can lid may use the presentinvention. FIG. 7 illustrates a construction where a conventional insert35 is provided within an opening 36 in the can lid and this insert 35 ismodified by providing a score line 23x underneath the gate panel thesame as heretofore described. In such an arrangement, the insert panelis first formed as a conventional cup-shaped member, not shown, having aflange 37. This member is inserted into the opening 36 in the can lid L,with the flange 37 at the top surface. Thereafter, the offset panel G isformed underneath a spacer strip 22x. The spacer strip 22x will lieagainst the undersurface of the lid about the lid opening 36 and thespacer strip will connect with the gate panel G wherein a score line 23xis cut as heretofore described.

In the construction of a conventional insert, a synthetic resin plasticseal 38 is provided at the underside of the can lid and about the edgeof the insert to secure the insert in place with a leakproof fit.However, to complete the unit, a sealer-filler 30 is then placed in theaperture formed in this insert, and a fillet 32 will form in thisaperture the same as heretofore described. Also, wax will flow throughthe lap 27x and thence through the lanced portion, not shown, and aboutthe score line 23x underneath the gate as a bead 33x.

FIG. 8 illustrates another arrangement of a gate G in a lid L which issimilar to the construction shown at FIG. 4 excepting the gate G israised by an upsloping wall 40 at the aperture to provide a central dome41 which may lie in the plane of the lid, or even above that plane, tofacilitate pushing the gate panel against the score line to open it. Awax sealer-filler is applied to the aperture 21 in the channel about thegate between the aperture 21 and the upsloping wall 40, as heretoforedescribed. The sealer-filler 30 will flow into the lap 27 and through alance opening 25, as heretofore described. Thence, the wax will fiowabout the score line 23 where metal is exposed. v

This FIG. 8 also shows the manner in which the wax sealer-filler may bespread over the undersurface at any selected area of the lid and gatewhenever a suitable fluxing agent is applied to the area. The area,illustrated at FIG. 8, is exemplary of a desirable portion to be coveredby the wax layer 42, that is, at the edge of the gate panel G where thefolded spacer strip is located and at a portion of the lid adjacent tothis panel edge where a fillet 43 forms between the underfold andunderside of the can lid. The wax applied to the lid at the top of theaperture will thus flow through the lanced opening and thence about thescore line and over the selected area as at 42, which may be the entiregate panel. Also, if sufficient wax is used, a wax covering may coverthe top of the gate panel.

FIGS. 9 and 10 show a construction of a gate G formed within an insertsuch as shown at FIG. 7. The gate G shown in this insert 35, FIG. 10,differs from the gate G shown at FIG. 7, in that a raised central dome41 is provided in the face of the gate. A further modification occurs byproviding a channel 45 in the lid L at the peripheral edge of the insertwith the edge of the top insert flange 37 reaching and turning into thischannel 45, as illustrated. With this arrangement, whenever a waxsealerfiller is applied to the gate, a small amount of additional waxcan be applied in this channel as at 46 to seal the lapping edge of theinsert, as illustrated. This procedure will.permit the sealant to flowbetween the flange 37 and can lid to seal the insert and eliminate thecomparatively expensive plastic seal 38 shown at FIG. 7.

The modified constructions at FIGS. 11 and 12 depict a can lid having agate G which is substantially the same as the gate illustrated at FIG.8. However, the score line 23a is at the upper surface of the gate inthe fold 27 between the gate surface and the spacer strip 22, such beingbest illustrated at FIG. 12. In this unit, the filler-sealer will form afillet in the channel between the inclined wall 40 of the gate G and theedge of the aperture 21. It is to be noted that no metal surfaces willbe exposed at the underside of the lid except at the lance 25, andaccordingly, when the sealer-filler is applied to this structure, a plug31 will form in the lance opening 25 and need not spread further.

The construction shown at FIGS. 13 15 illustrates a gate G which isformed in the face of a lid L" without providing for a spacer stripbelow an aperture. The outline of the gate G is defined by a'score line23" at the upper surface of the lid L. This score line 23" is at thebottom of a channel 50 which assumes the same form as the gate. Forexample, the gate is illustrated in the drawing as being circular andaccordingly, the channel is also circular. This score line 23" isinterrupted by a hinge portion 24" at the side of the gate adjacent tothe center of the can, as heretofore described, and a lance opening 25"is located diametrically opposite to this hinge. Accordingly, the gatemay be opened by pushing it downwardly at the edge adjacent to thelanced opening to tear the metal at the score line as the gate movesinto the can away from the lid.

A wax sealer-filler 30 may be used to fill this channel 50, as bestillustrated at FIG. 14, and the sealerfiller will also seal off thelanced opening 25". To prevent the pressure of the contents within a canfrom blowing out the wax sealer-filler at the lanced opening, an edgeportion of this gate at the lanced opening underlies the adjacentaperture portion of the can lid as a small tab 51, as illustrated inbroken lines at FIG. 13 and also at FIGS. 14 and 15. This tab is formedby stretching the metal of the gate adjacent to the lanced portion sothat it may provide for a lap 27". Although the material forming the tab51' will be formed under considerable pressure, the resulting lap27"'will not fit against the underside of the channel 50 in a perfectmanner and when a wax sealer-filler is applied to the channel 50, itwill flow through this lap portion by simple capillary action to set upas a fillet 52 at the underside of the gate, as best illustrated at FIG.14. The tendency for leaks to occur will thus be minimized since thethin layer of wax between the overlapping portions of the gate and canlid, at the channel, will prevent a leak flow from this opening 25. Theunderlapping of the tab 51 forms a backing surface for this thin layerof sealant and also constitutes a reinforcement to resist pressure.

The steps for forming this tab 51 and the lap 27" are illustrated atFIGS. 16 through 19. The first step of operation is to draw the channel50 which has an arcuate cross section as shown at FIG. 16. The secondstep, shown at FIG. 17, is to select and to form an enlargement 53 ofthe metal at the location of the projected tab, adjacent to the pointwhere the gate will be lanced. Next, the score line 23 may be cut toform the outline of the gate. Next, a short portion of the score line,at the enlargement 53, is lanced, as shown at FIG. 18. Finally, thislanced portion is compressed, or bumped in any suitable manner, notshown, to form the overlap of the tab. This stretched metal forming thetab underlies the lid at the lanced portion, as illustrated at FIG. 19,and the final step of operation will be to fill the channel with sealantas heretofore mentioned.

The construction shown at FIGS. and 22-15, discloses a can lid L with agate H having an offset panel 60 underneath a horseshoe shaped aperture.The horseshoe form of the aperture includes opposing sides 61 whichconverge tangentially from a circular end portion 62. The constructionshown at FIG. 21 discloses a can lid L having a pair of smaller gates H,at opposite sides of the can, each of which is, for all purposes,identical to the gate H shown at FIG. 20, excepting that the opposingsides 61' of each gate extend in spaced parallelism from a circular endportion 62'. The horseshoe shapes shown are merely exemplary of othershapes, such as a triangle, a truncated teardrop, a rectangle or thelike.

As best shown at FIGS. 23 and 24, the gate structure about the horseshoeshaped aperture edge 61 and 62 is substantially identical to thatheretofore described with an underfolded spacer strip 22h about theedges 61 and 62 of this aperture with the gate panel 60 lying beneaththis spacer strip 2211 and connecting therewith by an outer edge fold26/1. A score line 2311 at the underside of the panel is alsosubstantially the same as heretofore described, extending about thatportion of the panel underneath the spacer strip 22h. This score line islanced as at 2511, adjacent to the center of the circular end of theaperture 62.

The folded portions to define the spacer strip 22h terminate at theextended ends of the straight sections of the aperture, and the reachbetween these extended ends is a sloping offset will 64 between thesurface of the lid L and the panel 60. The hinge 2411 is located at thebottom of this wall 64 as best indicated at FIG. 23.

It follows that the underfolded spacer strip 22h, terminating at theextended ends of the straight sections, will taper from a maximum widthas shown at FIG. 24, to

a vestige 65 as shown at FIG. 25, and then fair into the offset =-wallportion 64. V 3 V A sealer-filler 30 will be applied to the gate panel60, the same. as heretofore described, to produce a plug 31 at thelanced portion 25h and a fillet 32 at the aperture edge 61-62. It willalso produce a modified fillet 32h at the hinge. 2411. Thissealer-filler, of suitable microcrystalline wax or like material, willflow into the lap 2711 between the spacer strip 2211 and the panel 60,thence through the lanced opening 25h and thence about the score line2311 as a filler 3311, the same as heretofore described.

FIGS. 26 28 indicate diagrammatically certain steps which may be used ina method for forming the gate H shown at FIG. 20. FIG. 26 indicates oneof the first steps by forming a rounded indentation 66 in the can lid Lto stretch the metal where the gate is to be located. FIG. 27illustrates a subsequent step of forming the panel 60, the offset wall64 and a wall section 67 between the panel 60 and the gate lid L whichwill subsequently form the spacer strip 2211. FIG. 28 shows a subsequentstep where the wall section 67 is flattened to produce the spacer strip2211 between the gate panel 60 and the lid L.

I have now described my invention in considerable detail. However, it isobvious that others skilled in the art can build and devise alternateand equivalent constructions which are nevertheless within the spiritand scope of my invention. Hence, I desire that my protection be limitednot by the constructions illustrated and described, but only by theproper scope of the appended claims.

I claim:

1. In a can lid having a pushdown gate defined by a score line in theface of the lid, which is torn and severed when the gate is pusheddownwardly into the can, and a small, narrow, lanced opening at thescore line to facilitate the initiation of the tearing and severing ofthe score line whenever the gate is pushed downwardly, a sealingarrangement including:

a portion of the can lid folded against and lapping over the gate at thelanced opening to constitute a back-up surface at the lanced opening;

an offset in the outer surface of the can adjacent to the lanced openingforming an indentation; and

a wax-like sealer-filler, of a type which may be obtained as a settablefluid, extending continuously from the indentation as a fillet, thencebetween the back-up surfaces as a capillary layer and thence into thelanced opening as a plug.

2. In the organization defined in claim 1 wherein:

the sealer-filler is a blend of paraffin waxes.

3. In the organization defined in claim 1 wherein:

the sealer-filler is a polymeric sealant having the generalcharacteristics of a thermo-setting poly epoxy which may be applied tothe lid in a liquid state to facilitate the flowing of the same into thelanced opening and between the lapping surfaces through capillaryaction.

4. In the organization defined in claim 1 wherein:

the sealer-filler is a polymeric sealant having the generalcharacteristics of a thermo-plastic ethylene vinyl acetate copolymerwhich may be heated to a liquid state and applied to the can lid topermit the same to flow between the lapped surfaces and thence into thelanced opening by capillary action.

5. In the organization defined in claim 1 wherein:

at the score line and said sealer-filler extends into the channel as afillet to prevent foreign substances from collecting in the channel. 7.1n the organization defined in claim 1 wherein: the score line is at theunderside of the bid and said sealer-filler plug extends through thelanced opening and into the score line.

1. In a can lid having a pushdown gate defined by a score line in theface of the lid, which is torn and severed when the gate is pusheddownwardly into the can, and a small, narrow, lanced opening at thescore line to facilitate the initiation of the tearing and severing ofthe score line whenever the gate is pushed downwardly, a sealingarrangement including: a portion of the can lid folded against andlapping over the gate at the lanced opening to constitute a back-upsurface at the lanced opening; an offset in the outer surface of the canadjacent to The lanced opening forming an indentation; and a wax-likesealer-filler, of a type which may be obtained as a settable fluid,extending continuously from the indentation as a fillet, thence betweenthe back-up surfaces as a capillary layer and thence into the lancedopening as a plug.
 2. In the organization defined in claim 1 wherein:the sealer-filler is a blend of paraffin waxes.
 3. In the organizationdefined in claim 1 wherein: the sealer-filler is a polymeric sealanthaving the general characteristics of a thermo-setting poly epoxy whichmay be applied to the lid in a liquid state to facilitate the flowing ofthe same into the lanced opening and between the lapping surfacesthrough capillary action.
 4. In the organization defined in claim 1wherein: the sealer-filler is a polymeric sealant having the generalcharacteristics of a thermo-plastic ethylene vinyl acetate copolymerwhich may be heated to a liquid state and applied to the can lid topermit the same to flow between the lapped surfaces and thence into thelanced opening by capillary action.
 5. In the organization defined inclaim 1 wherein: the gate is at an underfold below an aperture in thecan lid with the edge of the underfold defining the aforesaidindentation, and wherein the sealer-filler extends completely about thisunderfolded edge as a fillet to prevent foreign substances fromcollecting in the aperture.
 6. In the organization defined in claim 1wherein: the indentation comprises a channel about the gate at the scoreline and said sealer-filler extends into the channel as a fillet toprevent foreign substances from collecting in the channel.
 7. In theorganization defined in claim 1 wherein: the score line is at theunderside of the bid and said sealer-filler plug extends through thelanced opening and into the score line.